1.
Liquid penetrant inspection requires that the liquid possess a __________ surface tension.
Correct Answer
B. Low
Explanation
Liquid penetrant inspection is a nondestructive testing method used to detect surface defects in materials. In this process, a liquid penetrant is applied to the surface of the material and allowed to seep into any surface defects. To ensure effective penetration, the liquid must have a low surface tension. Low surface tension allows the liquid to spread evenly over the surface and penetrate into small cracks and defects. Therefore, a low surface tension is an important requirement for the liquid used in liquid penetrant inspection.
2.
In Canada, NDE personnel are trained and certified to which standard?
Correct Answer
C. CGSB 48.9712
Explanation
In Canada, NDE personnel are trained and certified to the CGSB 48.9712 standard. This standard is specifically designed for non-destructive examination (NDE) personnel and covers the requirements for training, certification, and qualification of NDE personnel. It ensures that NDE personnel in Canada have the necessary skills and knowledge to perform their job effectively and safely.
3.
The function of an emulsifier is to:
Correct Answer
C. Render the excess post-emulsifiable penetrant water-washable
Explanation
An emulsifier is a substance that helps to mix two immiscible substances, such as oil and water. In the context of penetrant testing, an emulsifier is used to render the excess post-emulsifiable penetrant water-washable. This means that it helps to remove the excess penetrant from the surface being tested by allowing it to mix with water and be easily washed away. By rendering the penetrant water-washable, the emulsifier ensures that any indications or defects are clearly visible and not obscured by excess penetrant.
4.
The forerunner to modern PT was known as the:
Correct Answer
B. Oil and whiting method
Explanation
The correct answer is "oil and whiting method." The question is asking for the forerunner to modern PT (Penetrant Testing) methods. The oil and whiting method refers to a technique used in the past where a penetrating oil, often mixed with a white powder called whiting, was applied to the surface of a material. This method allowed for the detection of surface defects or cracks by the oil penetrating into these areas and making them visible. This method was later refined and evolved into the modern PT techniques used today.
5.
Pre-cleaning in PT refers to:
Correct Answer
D. Both (a) and (c)
Explanation
Pre-cleaning in PT refers to ensuring that the surface of the material is free of contaminants and ensuring that a discontinuity is free of contaminants. This means that before performing penetrant testing, it is necessary to clean the surface of the material to remove any dirt, grease, or other contaminants that could interfere with the inspection process. Additionally, if there is a discontinuity or defect on the surface, it should also be cleaned to ensure that the penetrant can properly enter and highlight the defect during testing.
6.
Dwell time is:
Correct Answer
D. None of the above
Explanation
The discontinuity must be open to the surface for penetrant to enter.
7.
The physics that enables the penetrant to enter into a discontinuity is called:
Correct Answer
C. Capillary force
Explanation
Capillary force is the physics that enables the penetrant to enter into a discontinuity. Capillary force is the phenomenon where a liquid is drawn into a narrow space against the force of gravity. This force is caused by the adhesive and cohesive properties of the liquid, which allow it to climb up narrow spaces, such as the cracks or discontinuities in a material. Therefore, capillary force is responsible for the penetrant being able to enter into a discontinuity.
8.
Black-light intensity is stated as a minimum of 1000 microwatts per centimeter squared. Why?
Correct Answer
D. To ensure the fluorescent dye reaches its peak fluorescence
Explanation
The black-light intensity is stated as a minimum of 1000 microwatts per centimeter squared in order to ensure that the fluorescent dye reaches its peak fluorescence. When the black-light intensity is at this level, it provides the optimal conditions for the dye to emit the brightest fluorescence, making it easier for the operator to detect any defects or irregularities on the material surface. This level of intensity ensures that the dye is fully activated and visible, allowing for accurate inspection and evaluation.
9.
According to CGSB Standards, temperatures in hot air drying ovens should be maintained at
Correct Answer
A. Maximum 71 degrees Celsius
Explanation
According to CGSB Standards, hot air drying ovens should maintain a maximum temperature of 71 degrees Celsius. This temperature limit ensures that the drying process is effective without causing any damage or degradation to the materials being dried. It also helps to prevent any potential safety hazards that may arise from excessively high temperatures. Option 2, which suggests a temperature range of 16-43 degrees Celsius, is incorrect as it does not adhere to the specified maximum temperature limit. The statement that the dryer temperature should be as high as possible for faster drying is also incorrect as it disregards the safety and quality considerations outlined in the CGSB Standards.
10.
Dark adaptation is stated by most codes as a minimum of three minutes. Why?
Correct Answer
B. To allow the operator's eyes time to dilate for maximum seeing in the darkened inspection area
Explanation
Dark adaptation refers to the process by which the eyes adjust to low light conditions. When entering a darkened inspection area, the operator's eyes need time to dilate, or open up, in order to allow more light to enter the eye and improve visibility. This dilation of the pupils enables the operator to see better in the darkened environment and detect any visible dye penetrant indications. Therefore, a minimum of three minutes is required to allow the operator's eyes to fully dilate and achieve maximum seeing in the darkened inspection area.
11.
The most important property that enables the penetrant to enter into a discontinuity is:
Correct Answer
D. Surface tension
Explanation
Penetrability is determined by properties such as surface tension.
12.
Immersion dwell is used when:
Correct Answer
C. Extremely long dwell times are needed
Explanation
The correct answer is "extremely long dwell times are needed." Immersion dwell is a technique used in non-destructive testing where the test part is immersed in a liquid medium for a prolonged period. This method is employed when there is a need for extended dwell times to ensure thorough inspection. The other options mentioned, such as shallow and wide discontinuities and large numbers of test parts, do not specifically require the use of immersion dwell.
13.
"Inspection" can be performed by trainees, Level 2 and Level 3.
Correct Answer
A. True
Explanation
The statement suggests that trainees, Level 2, and Level 3 individuals are allowed to perform inspections. This implies that these individuals have the necessary skills and knowledge to carry out inspections effectively. Therefore, the answer is true.
14.
Developing time is a minimum of one-half of the penetrant dwell time.
Correct Answer
A. True
Explanation
The statement suggests that the developing time should be at least half of the penetrant dwell time. This means that the time taken to develop the penetrant should be longer than the time it takes for the penetrant to dwell on the surface being tested. This is important because it allows sufficient time for the penetrant to fully penetrate any flaws or defects in the material being tested. Therefore, the statement is true.
15.
Which of the following developers is the most sensitive?
Correct Answer
C. Non-aqueous developer
Explanation
A non-aqueous developer is the most sensitive developer among the given options. Non-aqueous developers are typically solvent-based and have a higher sensitivity compared to dry and aqueous developers. They are able to detect smaller defects and provide higher contrast images. Dry developers are typically used for magnetic particle testing and do not provide as high sensitivity as non-aqueous developers. Aqueous developers are water-based and have lower sensitivity compared to non-aqueous developers. Therefore, the non-aqueous developer is the most sensitive option.
16.
Which of the following developers is most suitable for parts that are complex or have rough surfaces?
Correct Answer
A. Dry developer
Explanation
Dry developer is the most suitable developer for parts that are complex or have rough surfaces because it is a powdered developer that can adhere to irregular surfaces and effectively highlight any surface defects or indications. It is commonly used in non-destructive testing methods such as liquid penetrant testing to enhance the visibility of indications on the surface of the test object. Aqueous developer is a water-based developer that is more suitable for smooth surfaces, while non-aqueous developer is a developer that is not water-based and may not adhere as well to complex or rough surfaces.
17.
Which of the following is the best reason why excessive drying of a part is not desired?
Correct Answer
C. A reduction in resolution may result
Explanation
Excessive drying of a part is not desired because it can lead to a reduction in resolution. When a part is excessively dried, it can cause the details and fine features of the part to become less clear and defined. This can negatively impact the overall quality and accuracy of the part. Therefore, it is important to avoid excessive drying in order to maintain a high level of resolution in the final product.
18.
The contrast ratios for visible penetrants and fluorescent penetrants are respectively:
Correct Answer
B. 6 to 1 and 300 to 1
Explanation
The correct answer is 6 to 1 and 300 to 1. This means that the contrast ratio for visible penetrants is 6 to 1, while the contrast ratio for fluorescent penetrants is 300 to 1. The contrast ratio refers to the ability of the penetrant to create a visible contrast with the background, making it easier to detect any defects or discontinuities. A higher contrast ratio indicates a better ability to detect flaws.
19.
The notable difference between phosphorescence and fluorescence is:
Correct Answer
B. Persistence after applied radiation
Explanation
Phosphorescence and fluorescence differ in terms of persistence after applied radiation. Phosphorescence refers to the emission of light that continues even after the excitation source is removed, while fluorescence only emits light as long as the excitation source is present. This means that phosphorescent materials can continue to glow in the dark, while fluorescent materials stop emitting light as soon as the excitation source is turned off.
20.
When preparing an acid solution for precleaning, you should:
Correct Answer
A. Add the acid to water
Explanation
When preparing an acid solution for precleaning, it is important to add the acid to water rather than the other way around. This is because adding water to acid can cause a violent reaction, resulting in the mixture splashing or boiling. By adding the acid to water slowly and in a controlled manner, the reaction is less likely to be hazardous.
21.
An important function of emulsification is:
Correct Answer
B. Improve signal-to-noise ratio
Explanation
Emulsification refers to the process of mixing two immiscible substances, such as oil and water, to form an emulsion. In the context of improving signal-to-noise ratio, emulsification can be understood as a technique used in various fields, including photography and audio engineering, to reduce the amount of noise or interference in a signal. By creating a stable emulsion, the unwanted noise or interference is dispersed or suppressed, resulting in a clearer and more accurate signal. Therefore, improving the signal-to-noise ratio is an important function of emulsification.
22.
Specific gravity is checked using a:
Correct Answer
B. Hydrometer
Explanation
A hydrometer is used to measure the specific gravity of a liquid. It works based on the principle that the density of a liquid is directly proportional to its specific gravity. The hydrometer is a cylindrical glass tube with a weighted bulb at the bottom. When placed in a liquid, it floats and the level at which it sinks indicates the specific gravity of the liquid. Therefore, a hydrometer is the correct tool for checking specific gravity.
23.
Dyes used in fluorescent penetrant fluoresce in the:
Correct Answer
B. Yellow-green
Explanation
The dyes used in fluorescent penetrant fluoresce in the yellow-green color. This means that when exposed to certain wavelengths of light, these dyes emit a yellow-green glow. This property is utilized in fluorescent penetrant testing, where the dye is applied to a surface and any defects or cracks in the material can be easily detected by the fluorescence.
24.
Viscosity is measured in units called:
Correct Answer
C. Centistokes
Explanation
Viscosity is a measure of a fluid's resistance to flow. Centistokes is a unit commonly used to measure viscosity. It represents the kinematic viscosity, which is the ratio of a fluid's dynamic viscosity to its density. The higher the centistoke value, the more viscous the fluid is. Dynes/cm is a unit of surface tension, mm/sec is a unit of speed, and milligrams per cc is a unit of density, none of which directly measure viscosity. Therefore, centistokes is the correct unit for measuring viscosity.
25.
The sensitivity of a liquid penetrant system is determined by:
Correct Answer
C. Ability to detect small defects
Explanation
The sensitivity of a liquid penetrant system refers to its capability to detect small defects. This means that a highly sensitive system can identify even the smallest flaws or imperfections in the material being tested. Contrast ratios and color intensity may contribute to the system's effectiveness, but the primary factor determining sensitivity is its ability to detect small defects. The frequency of black-light used is not mentioned in the question and therefore cannot be considered as a factor in determining sensitivity.
26.
The amount of white light in a darkened inspection area must not exceed 2 ftc
Correct Answer
A. True
Explanation
2 ftc (footcandles) = 20 lux
27.
The most important factor which determines the speed penetrant enters a discontinuity is based on viscosity.
Correct Answer
A. True
Explanation
The ability of the penetrant to enter the discontinuity is based on surface tension; however, the speed at which it enters is determined by viscosity.
28.
Black light intensity must be a maximum of 1000 microwatts per centimeter squared.
Correct Answer
B. False
Explanation
Black light intensity must be a MINIMUM of 1000 microwatts per centimeter squared, not maximum.
29.
The meniscus test is used to determine fluorescent ability in thin films.
Correct Answer
A. True
Explanation
The meniscus test is a method used to assess the fluorescent ability of thin films. This test involves observing the curvature of the liquid surface in contact with the film. If the film exhibits fluorescence, it will cause a change in the shape of the meniscus. Therefore, the statement that the meniscus test is used to determine fluorescent ability in thin films is true.
30.
Flash point values of a penetrant should be as high as possible.
Correct Answer
A. True
Explanation
A high flash point value for a penetrant is desirable because it indicates that the penetrant is less likely to evaporate or ignite at lower temperatures. This is important for safety reasons, as a penetrant with a low flash point could pose a fire hazard during application or storage. Additionally, a higher flash point value ensures that the penetrant remains in its liquid state for a longer period of time, allowing it to effectively penetrate and detect flaws in the material being tested. Therefore, it is true that the flash point values of a penetrant should be as high as possible.
31.
Contact angle relates to:
Correct Answer
C. The angle at which a liquid sits on a material surface
Explanation
Contact angle relates to the angle at which a liquid sits on a material surface. This angle is determined by the balance between the adhesive forces between the liquid and the surface, and the cohesive forces within the liquid. A high contact angle indicates that the liquid is less likely to spread out on the surface, while a low contact angle indicates that the liquid will spread out more easily. The contact angle is important in various applications, such as determining the wettability of a surface or understanding the behavior of liquids on different materials.
32.
A water tolerance test is used to determine:
Correct Answer
B. How much water a postemulsifiable penetrant or a hydropHilic emulsifier can tolerate before becoming unusable
Explanation
A water tolerance test is used to determine how much water a postemulsifiable penetrant or a hydrophilic emulsifier can tolerate before becoming unusable. This test helps to establish the maximum amount of water that can be present in the penetrant or emulsifier without affecting its effectiveness. By conducting this test, one can ensure that the penetrant or emulsifier is able to withstand a certain level of water contamination and still perform its intended function.
33.
Why is a black light filter necessary?
Correct Answer
D. None of the above
Explanation
A black light filter is not necessary to activate the fluorescent penetrant dye because the dye is activated by the UV light emitted by the black light bulb itself. It is also not necessary to provide a contrasting background on the material surface as the black light already highlights any fluorescence present on the surface. Additionally, it is not needed to protect the black light bulb from scratches and breakage as this is not its purpose. Therefore, the correct answer is "none of the above".
34.
Which of the following is generally accepted as the most important precaution when using a solvent-removable penetrant?
Correct Answer
C. Do not use excessive amount of solvent
Explanation
Using an excessive amount of solvent when using a solvent-removable penetrant can have negative effects. It can lead to excessive removal of the penetrant from the surface, making it difficult to detect any defects. This can result in false-negative results and compromise the effectiveness of the inspection process. Therefore, it is generally accepted that using an excessive amount of solvent should be avoided as a precautionary measure.
35.
When penetrant testing, the temperature of the test area should not be lower than:
Correct Answer
D. 5 degrees Celsius
Explanation
The correct answer is 5 degrees Celsius because penetrant testing is a non-destructive testing method used to detect surface defects in materials. In order for the penetrant to effectively flow into any surface defects, the test area needs to be above a certain temperature. If the temperature is too low, the penetrant may not flow properly and the defects may not be detected. Therefore, the temperature of the test area should not be lower than 5 degrees Celsius.
36.
Emulsifier time:
Correct Answer
C. Is extremely important and will greatly affect test results
Explanation
The given answer states that the emulsifier time is extremely important and will greatly affect test results. This implies that the amount of time the emulsifier is allowed to act on the surface has a significant impact on the outcome of the test. The longer the emulsifier time, the better the results are expected to be. It suggests that the emulsifier plays a crucial role in the process and should not be overlooked or rushed.
37.
Sulphur and chlorine found in penetrants are detrimental to:
Correct Answer
C. Nickel
Explanation
Sulphur and chlorine found in penetrants are detrimental to nickel. These elements can cause corrosion and damage to the surface of nickel, leading to degradation of the material. This is why it is important to avoid using penetrants containing sulphur and chlorine on nickel surfaces to maintain their integrity and prevent any potential harm.
38.
Penetrants may be applied by:
Correct Answer
D. All of the above
Explanation
The correct answer is "all of the above" because penetrants can be applied by brushing, dipping, or pouring. Brushing involves using a brush to apply the penetrant onto the surface, dipping involves immersing the object into a container filled with the penetrant, and pouring involves pouring the penetrant directly onto the surface. All of these methods can effectively apply penetrants depending on the specific requirements and the nature of the object being tested.
39.
Which of the following is an advantage of fluorescent penetrants over visible dye penetrants?
Correct Answer
B. Smaller indications are more easily seen
Explanation
Fluorescent penetrants have the advantage of being able to detect smaller indications more easily compared to visible dye penetrants. This is because fluorescent penetrants emit a bright glow under UV light, making even small indications more visible and easier to identify during inspection.
40.
Why is it advisable to have an ultraviolet light installed at the wash station?
Correct Answer
C. To check the effectiveness of the wash cycle
Explanation
Having an ultraviolet light installed at the wash station allows for the inspection of parts without the need for drying. This is because ultraviolet light can reveal any fluorescent dye penetrant that may be present on the parts. By using the ultraviolet light, one can determine if the wash cycle has been effective in removing any remaining dye penetrant from the parts. This helps ensure that the parts have been properly cleaned and prepared for further processes or use.
41.
Which of the following is most likely to render the postemulsification test ineffective?
Correct Answer
C. The emulsifying time is too long
Explanation
The postemulsification test is used to detect defects or cracks in materials by applying a penetrant, emulsifying it, and then removing the excess. If the emulsifying time is too long, it can cause the penetrant to be completely removed from the cracks or defects, rendering the test ineffective as it will not be able to detect any flaws.
42.
Which of the following characteristics does not apply to liquid penetrant testing?
Correct Answer
A. This method can accurately measure the depth of a crack or discontinuity
Explanation
Liquid penetrant testing is a nondestructive testing method used to detect surface discontinuities in materials. It involves applying a liquid penetrant to the surface of the material, allowing it to seep into any surface cracks or defects, and then removing the excess penetrant. The penetrant is typically brightly colored to make it visible under UV light. However, liquid penetrant testing is not capable of accurately measuring the depth of a crack or discontinuity. It can only detect the presence of surface defects, making it more suitable for finding shallow surface discontinuities rather than measuring the depth of cracks.
43.
Which of the following discontinuities is most likely to be missed due to improper rinse techniques?
Correct Answer
C. Shallow and broad discontinuities
Explanation
Shallow and broad discontinuities are most likely to be missed due to improper rinse techniques. This is because these types of discontinuities are not as pronounced or easily visible as other types such as a forging lap or deep pitting. Improper rinse techniques can result in inadequate removal of the penetrant from the surface, making it difficult to detect these shallow and broad discontinuities.
44.
The ability of a liquid to wet a surface is measured by contact angle, i.e. the angle between the liquid and the surface at the point of contact as the liquid advances. Good penetrants should have:
Correct Answer
A. A very small contact angle
Explanation
A small contact angle indicates that the liquid has a high wetting ability and can spread easily on the surface. This is desirable for good penetrants as it allows them to effectively penetrate into small cracks and crevices. A large contact angle would indicate poor wetting ability and limited penetration. Therefore, a very small contact angle is preferred for good penetrants.
45.
The tendency of a liquid penetrant to enter a discontinuity is primarily related to:
Correct Answer
B. The capillary forces
Explanation
The tendency of a liquid penetrant to enter a discontinuity is primarily related to the capillary forces. Capillary forces refer to the phenomenon where a liquid can be drawn into narrow spaces or tubes against the force of gravity. In the case of liquid penetrant testing, capillary forces allow the penetrant to flow into small cracks or defects in a material, making them visible during the inspection process. The viscosity, chemical inertness, and specific gravity of the penetrant may also play a role, but the capillary forces are the main factor determining the penetrant's ability to enter discontinuities.
46.
Acids and chromates should not be left on the surface of parts that will be inspected with a water-washable fluorescent penetrant because:
Correct Answer
C. They may kill the fluorescence of the penetrant
Explanation
Acids and chromates should not be left on the surface of parts that will be inspected with a water-washable fluorescent penetrant because they may kill the fluorescence of the penetrant. This means that if acids and chromates are present on the surface, they can interfere with the ability of the penetrant to emit fluorescent light when exposed to ultraviolet radiation. This can make it difficult or impossible to detect any defects or discontinuities in the parts being inspected. Therefore, it is important to ensure that the surface is free from any substances that may inhibit the fluorescence of the penetrant.
47.
Both fluorescent and visible dye penetrants are identified by:
Correct Answer
D. Method of removal
Explanation
The correct answer is method of removal. Both fluorescent and visible dye penetrants can be identified based on the method of removal. This refers to how the penetrant is removed from the surface after the inspection process. The method of removal can vary depending on the type of penetrant used and the specific application. It is an important factor to consider as it can affect the overall effectiveness and efficiency of the inspection process.
48.
Which of the following is the best reason why excessive drying of a part is not desired?
Correct Answer
C. A reduction in resolution may result
Explanation
Excessive drying of a part is not desired because it may result in a reduction in resolution. This means that the details and clarity of the part may be compromised, leading to a lower quality outcome.
49.
Black light used in penetrant testing has its peak at:
Correct Answer
D. 3650 angstroms (365 nm)
Explanation
Black light used in penetrant testing has its peak at 3650 angstroms (365 nm). This wavelength is specifically chosen because it falls within the ultraviolet (UV) range, which is invisible to the human eye. The fluorescent penetrant used in this testing method absorbs the UV light and re-emits it at a longer wavelength, typically in the visible range, making any defects or cracks in the material more visible. By using a black light with a peak at 3650 angstroms, the penetrant is able to fluoresce at a wavelength that is easily detectable by the human eye.
50.
Black light is considered to be in the range of:
Correct Answer
A. Long wavelength ultraviolet
Explanation
Black light is considered to be in the range of long wavelength ultraviolet because black light emits ultraviolet (UV) radiation that is close to the visible light spectrum. Long wavelength ultraviolet refers to UV-A, which has a longer wavelength compared to UV-B and UV-C. Black light emits UV-A radiation, typically in the range of 315 to 400 nanometers, which is not visible to the human eye but can cause certain materials to fluoresce or glow.